Currently, it is known to make various handheld electronic devices such as mobile phones, e-readers, and tablet computers and similar devices. It is important to the user that such devices have a lightweight construction so that they are readily portable. Many known handheld electronic devices incorporate a plurality of lightweight components in order to reduce the weight of the device. For example, known handheld electronic devices include housing components such as a chassis, which supports the screen, battery, central processing unit (CPU) and other electronic hardware, a back cover, a front cover, an intermediate hardware enclosure, and a protective case. Such housing components are typically composed of solid plastics material, which may be fiber reinforced or unreinforced, and/or solid lightweight metals.
The plastics materials include polycarbonate, having a typical density of 1.2 g/cc, and fiber reinforced polycarbonate, having a typical density of 1.4 g/cc. Such plastics are used due to their properties of low density, stiffness, damage resistance and tolerance, and ability to be formed or moulded into three-dimensional shapes.
The lightweight metals include aluminum, having a typical density of 2.7 g/cc, and magnesium, having a typical density of 1.7 g/cc. These particular metals are used due to their low density relative to other common metals.
It is current known in the art to employ solid metal and plastics material, either unreinforced or fiber reinforced, in the form of castings to obtain the desired component shape. The casting may additionally be subjected to computer numeric control (CNC) machining to incorporate fine details in shape and configuration, in particular to trim excess material, form cavities, and remove non-essential material to achieve further weight reduction. In some applications, external components which include a surface visible to the user may receive an aesthetic coating or treatment in order to enhance the aesthetic appearance and sensory feel of the device by the end user.
As newer models of handheld electronic devices are introduced, the achievement of even greater weight reduction is a key selling point, in addition to the provision of the desired functional capabilities of these devices. However, the achievement of reduced weight must not compromise the achievement of the essential functional and aesthetic requirements of the handheld electronic device, in particular the need for the housing components to exhibit suitable stiffness, damage tolerance, and the desired end user experience of the unit.
There is a need in the art for a housing component of a handheld electronic device which can provide not only reduced weight but also increased mechanical performance, in particular stiffness and resistance or tolerance to damage.
There is also a need in the art for a housing component of a handheld electronic device which can provide reduced weight as compared to known such housing components without compromising mechanical performance, so that the overall unit weight of the handheld electronic device can be reduced.
There is furthermore a need in the art for a housing component of a handheld electronic device which can provide the combination of reduced weight and improved or equivalent mechanical performance without substantially increasing, or even reducing, the unit cost of the housing component.